(a) Field of the invention
This invention generally relates to breast pumps and to improvements in breast pump operation with regard to interaction between pump and the breast of a mother. More specifically, the invention relates to a novel insert for conventional breast pumps of the type comprising a suction means which may be operated manually or mechanically, e.g. electrically, and having a milk reservoir which may but need not serve as the milk recipient portion of a baby feeding-bottle.
(b) Description of the prior art
Manually and mechanically operated breast pumps of the above mentioned type have been disclosed, for example, in our U.S. Pat. No. 4,573,969 as well as in our U.S. Application Ser. No. 06/711,676 and our GB - A - No. 8506679, and may include an insert for improved adaption of the suction bell made of a generally rigid material, such as glass or an organic polycarbonate, to a mother's breast.
Further, U.S. Pat. No. 3,977,405 teaches use of an annular insert made of an elastomer, e.g. rubber, for stabilizing the nipple or, actually, the nipple position within the suction bell made of a generally rigid organic polymer.
Another type of a soft insert in a breast pump having a rigid suction bell is disclosed in U.S. Pat. No. 3,822,703 and is a circular diaphragm in sealing connection with the suction bell; the diaphragm is provided with a central aperture dimensioned such that but the nipple area of the breast may extend therethrough; another breast pump with a diaphragm-type contact face for the nipple-encompassing area is disclosed in U.S. Pat. No. 2,542,505 but in either case the membrane has a substantially uniform thickness and is opaque.
Other types of breast pumps, i.e. those comprising a suction bell of an opaque and relatively non-rigid material, such as rubber, have been disclosed in U.S. Pat. No. 4,323,067 as well as in French Pat. No. 1,067,421 and include a deformable portion for contact with the nipple-encompassing area of a mother's breast which portion may be integrally connected with the suction bell or may be formed as an insert for same but in either case is subject to an above-ambient pressure applied from the backside of the deformable portion.
Finally, breast-contact pieces made of an opaque and deformable material for connection with a pump or pump recipient and entirely without support by an external suction bell or "flange" have been disclosed in French Pat. No. 1,091,809.
Obviously, a pump that includes a deformable contact portion in the nipple-encompassing area could be capable of simulating the "suckling" effect of palate and mouth of a baby and the advantages of such "simulating" pumps have been postulated for more than 30 years.
Yet, market researches made before the present invention seem to indicate a general user preference for breast pumps of the type having a suction bell formed of a rigid and heat resistant glass-like material because of their simple structure combined with transparence or translucence of the main pump components so as to enable safe and easily controllable cleaning in the same way as baby feeding bottles are cleaned, i.e. by immersing milk-exposed breast pump components in boiling water and visual control of the results.